RU2304659C1 - Method for river flow regulation to provide flood control - Google Patents

Abstract

FIELD: hydraulic engineering, particularly stream regulation to prevent territory flooding during spring tide.

SUBSTANCE: method involves creating temporary storage ponds by installing tube-type heat-exchangers in transversal stations of river bed confluent with main river bed; hermetically connecting heat-exchangers with vent risers having different heights and communicated with atmosphere, wherein the vent risers are arranged in opposite river banks; providing active circulation of air having temperature below 0°C through heat-exchangers in season preceding spring tide; creating artificial ice dams due to water freezing at heat-exchanger sections; regulating ice dam thawing regime in spring period by heat-exchanger venting rate increase or decrease; accumulating water in temporary storage ponds in spring period to extend spring tide period and to smooth flood peak.

EFFECT: prevention of flooding of territories located in central and lower main river zones during spring tide periods, decreased ecological hazard due to elimination of territory alienation and decreased time of hydrological regime and fish living condition change.

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Description

The invention relates to the field of hydraulic engineering and water management and can be used, in particular, to prevent emergencies caused by spring flood.

There is a known method of regulating river flow, which consists in changing its natural regime for the most rational use of water resources in the national economy by constructing a dam in the transverse section of the river valley — forming a reservoir and redistributing runoff from high-water seasons to low-water ones by seasonal accumulation of water in the reservoir with subsequent water withdrawal to the required volume in accordance with water consumption (Pleshkov YF Regulation of river flow. Water management calculations. Third edition, corrected and revised .-- L .: Gidrometeoizdat, 1975, pp. 106-108). The regulation of river flow in the reservoir also provides reliable protection against flooding of the downstream territories during floods and floods in cases where its regulating capacity is sufficient to receive the entire volume of flood flow and the formation of water discharge on the catchment area below the target section excludes its flow to I understand.

The disadvantages of the known solutions are:

- the high cost of constructing a reservoir, in which the creation of reservoirs only for flood control becomes inexpedient, especially since the formation of water discharge on the catchment area below the target section of the dam does not completely exclude the possibility of water entering the floodplain and flooding the territory;

- a significant change in the hydrological and hydrogeological regimes in the basin of the regulated river, which leads to environmental disruption and often to complete degradation of the natural biocenosis;

- a significant amount of land alienation, including forests and agricultural land, which significantly changes the ecological situation of the territory.

A water intake system is known from another field of technology (Patent RU No. 2254415, MPK7, EVB 9/04, published on 06/20/2005, Bull. No. 17), including a channel water intake with trash grids, gravity or siphon water conduits connecting it to the shore mesh well , combined or separate arrangement, a low-pressure barrier blocking with a complete channel blocking, moreover, the water intake water system is equipped with a heat exchanger installed in the transverse section of the roll below the site of the channel water intake, made in the form of a tubular ozduhovoda connected end portions with uneven risers, the riser is equipped with a greater height and the rotary damper has an outer thermal insulation, and is equipped with vertically mounted in the same alignment of the anchors. The tubular heat exchanger provides the formation of artificial ice, which, when the air temperature drops below 0 ° C, allows you to increase the water level relative to the ordinar, characteristic of the cold season. At the same time, in the area of intensive water withdrawal, water flow rates and turbulent activity of the stream decrease, which reduces the depth of involvement of the sludge and intra-water ice and completely eliminates the likelihood of freezing of the water intake and difficulties in its operation. During the period of freezing during the formation of a thick ice cover, the probability of freezing of water intake elements into the ice is excluded, which increases the reliability of the water intake facilities at low river water availability. The invention is used to improve the reliability of water withdrawal from rivers under moderate and severe conditions of water intake associated with exposure to intra-water ice in the pre-delivery period and with the threat of deep freezing of the river in the cold season in areas of intensive water withdrawal. At the same time, the possibility of flooding of the territory within the floodplain of the river during the flood period is not excluded.

Closest to the invention in terms of technical nature and the achieved technical effect is a known method of regulating water flow in the river catchment system for flood prevention (Patent RU No. 2116401, IPC 6 EV 3/02, publ. 07.27.1998), which consists in in natural depressions and other depressions, dams are used to receive flood waters for receiving flood waters, located at some distance from the river or located in the river bed, and flood areas are identified over the entire catchment area on these sections of riverbeds identify areas of flood flow formation, create an individual river flow regulation system for each flood flow formation site, for which the optimal number of temporary reservoirs formed using water-permeable reservoirs is determined for each flood flow formation site for the accumulation and storage of flood water and river animals of dams, for a specified number of temporary reservoirs, the parameters of the river flow regulation system are calculated for each section and flood flow formations, in all areas of flood flow formation, in accordance with the calculated parameters, river flow control systems are built, thereby ensuring safe flood-free runoff of flood floods accumulated in the river flow control systems over the entire catchment area.

A disadvantage of the known solution is the low efficiency due to the complexity of the operation of the cascade of reservoirs and their justification with significantly changing hydromorphological characteristics of the system, including:

- the complexity of predicting areas of the formation of flash flood or high water due to the fact that this process often takes place spontaneously, and the channel capacity constantly changes, including, for example, with the formation of ice jams;

- the difficulty of maintaining a constant flow capacity of dams located in the river channel or at some distance from it, due to the fact that the passage of the dam holes can be carried by large objects drawn by the flow, ice fragments and a decrease in the permeability of the dam body for water, despite the fact that the estimated permeability it is a determining parameter when choosing the alignment location of the downstream dam and reservoir capacity;

- the difficulty of maintaining a constant reservoir capacity due to the fact that during their operation gradual silting and entering by large entrained sediments (gravel, gravel) and cramps is not ruled out, despite the fact that the calculated reservoir capacity is a determining parameter when choosing the dam location site in the cascade .

The objective of the invention is the development of a new method of protecting territories from flooding during floods, ensuring the regulation of river flow by smoothing the peak of the flood due to the creation of temporary reservoirs on the river tributaries with the help of artificial ice dams and the accumulation of flood flood flow while reducing the environmental load on the environment.

The specified problem is solved as follows.

In the known method of regulating river flow to prevent flooding, which consists in the accumulation of flood water in temporary reservoirs formed by creating permeable dams in the channels, tubular heat exchangers are installed in the transverse sections of the river tributaries at the bottom level, hermetically connected to different-sized ventilation risers communicating with the atmosphere , which are located on opposite shores, in the pre-underwater period provide active ventilation of air at a pace artificial temperature below 0 ° C, through the heat exchangers and due to freezing of the runoff, form artificial ice dams; in spring, at a positive air temperature, the mode of ice melting is regulated by increasing or decreasing the ventilation intensity of the heat exchangers.

Distinctive features of the prototype are:

- in the transverse sections of the channels at the bottom level, tubular heat exchangers are installed, hermetically connected to the uneven ventilation struts, communicating with the atmosphere, which are placed on opposite banks;

- in the pre-underwater period, active ventilation of air having a temperature below 0 ° C is provided, through artificial heat exchangers and due to freezing of the runoff, form artificial ice dams;

- in the spring, at a positive air temperature, the melting mode of the ice is regulated by increasing or decreasing the ventilation intensity of the heat exchangers.

In the transverse sections of the channel at the bottom level, tubular heat exchangers are installed, hermetically connected to different-height ventilation risers that are connected to the atmosphere, which are placed on opposite banks, which allows you to control the temperature of the bottom soil and the bottom layer of water, and at negative air temperature provides the formation of icy hillocks - icy dams in the alignments of the installation of heat exchangers, and at a positive air temperature provides melting ice dams. At the same time, the costs of installing tubular heat exchangers are minimal, and land acquisition is not required.

In the pre-underwater period, active ventilation of air having a temperature below 0 ° C is provided, through the heat exchangers and due to freezing of the runoff, artificial ice dams are formed, this creates a backwater level in the upper pools of the ice dams, and a gradual accumulation of flood flow is ensured. Due to the overflow of water through the crests of the dams, only excess flow is discharged into the downstream waters, which should not exceed the total discharge rate of the water entering the floodplain in the main river channel. In order to achieve this correspondence, elevations of dam crests are increased by regulating the intensity of ventilation of heat exchangers or increase the number of ice dams on tributaries of the main river. This prevents flooding of the territory in the lower reaches of the river.

In the spring, at a positive air temperature, the regime of melting of ice is regulated by increasing or decreasing the intensity of ventilation of the heat exchangers, which ensures the regulation of the height of crests of ice dams, the volume of temporary reservoirs and, consequently, the duration of discharge during the flood period.

Thus, a causal relationship is ensured between the totality of the features of the claimed invention and the achieved technical result: regulation of river flow by smoothing the peak of the flood due to the creation of temporary reservoirs on the river tributaries using artificial ice dams and the accumulation of flood flow, which prevents flooding of the territories during the flood period, at the same time, the ecological load on the environment is reduced, since the alienation of lands is excluded, and the violation of the hydrological The hedgehog and fish habitat occurs only for a relatively short period.

An example of industrial applicability of the invention.

Figure 1-3 shows a longitudinal section of a section of the river (tributary of the main river) at the installation site of the tubular heat exchanger at different periods of time of development of the ice dam, figure 1 - at the end of the winter period before the flood; figure 2 - when conducting ventilation of a tubular heat exchanger and the formation of an icy hillock; figure 3 - during the flood period.

In the transverse section of the river - the inflow of the main watercourse at the level of bottom 6, a tubular heat exchanger 1 is installed, located in the transverse section. The tubular heat exchanger 1 is connected by end parts to unequal risers 2 installed on opposite banks, the open ends of the risers 2, communicating the heat exchanger 1 with the atmosphere, are located at marks that exclude the ingress of water into them during high water levels in the river. The riser 2 of greater height has thermal insulation made of a heat-insulating material, for example, dusting 3, and is equipped with a rotary damper 4. The heat exchanger 1 with an open damper 4 and an air temperature below 0 ° C provides the formation of an ice hill 5 at the bottom of the river 6, which when closed with the surface ice cover 7 of the river forms an icy dam. With an increase in the water level 8 in the river relative to ordinar 9, which is typical for unregulated conditions in the pre-flood period, a freezing zone of 10 soils is formed directly around the tubular heat exchanger 1 below the marks of the bottom of the river. In the alignment of the heat exchanger 1 vertically install anchors 11, buried in the bottom of the river and providing greater stability icy dam. When the water level 8 in the river rises, the ice cover 7 deforms and a fracture zone 12 forms in it. During the flood season, when snow melts actively, water at the ice dam location site as a result of backwater can reach the surface of the low floodplain 13 of the river. Arrows indicate the direction of water movement.

To prevent flooding of the territory caused by spring floods, tubular heat exchangers 1 are installed on erratic sections in the upper rivers - tributaries of the main watercourse along the channels of their channels. Tubular heat exchangers 1 can perform, for example, in the form of a tubular duct - one or two parallel pipes laid horizontally at the bottom of the river 6. The ends of the pipes of the heat exchanger 1 are hermetically connected to the vertical risers 2. To ensure active ventilation, the risers 2 are made uneven, around the riser 2 of greater height they are insulated, for example, in the form of earth dust 3. At the end of the winter period (Fig. 1), there is a river in front of the flood surface ice cover 7, and the water level corresponds to the ordinal 9, characteristic of natural unregulated conditions, while the damper 4 on the ventilation riser 2 is in the closed state, which prevents the ingress of cold th air in heat exchanger 1.

For the formation of an ice dam in front of the flood, the shutter 4 on the ventilation riser 2 is opened, while the air in the heat exchanger and having a positive temperature is replaced through the risers 2 by atmospheric air with a temperature below 0 ° C. Entering the pipes of the heat exchanger 1, cold air cools the surrounding soil in the channel part of the erratic section by heat transfer and passes to a riser 2 of a higher height, which has heat insulation 3, which holds the cooling process of the air heated in the pipes of the heat exchanger 1 with a higher temperature. a larger temperature gradient - the difference in air temperature in the risers 2 and, therefore, more active ventilation. When the soil is supercooled in the channel part of the erratic section in the installation site of the heat exchanger 1, a hillock 5 of bottom ice is formed (Fig. 2), into which freeze anchors 11 deep into the bottom of the river. In the period before high water at an unstable air temperature, when it can be higher than 0 ° С during the daytime, the shutter 4 is closed for this time, which stops ventilation, and the growth of the icy hillock 5 is stopped. The presence of anchors 11, buried in the bottom of the river, prevents uncontrolled erosion or demolition of the icy hill 5. In addition, a freezing zone of 10 soils is formed directly around the tubular heat exchanger 1 below the marks of the bottom 6 of the river. When the icy hillock 5 closes with the surface ice cover 7 of the river, an icy dam forms. Due to backwater, the water level 8 in the river rises relative to ordinar 9, which is typical for unregulated conditions in the pre-underwater period. In the area adjacent to the ice cover 7 to the ice dam, its partial destruction occurs and a fracture zone 12 of the ice cover 7 forms. Through this zone 12, water from the river flows to the surface of the ice cover 7 and, spreading in a thin layer, is discharged into the lower tail of the ice dam (direction of movement water is shown by arrows in figure 2).

When the air temperature drops below 0 ° C, in particular at night, freezing of water flowing in a thin layer through the crest of the ice dam occurs, and its height gradually increases. The created sub-level of water levels 8 in the upper pools of the icy dams provides a gradual accumulation of high-water flow. At the same time, the water level 8 on the tributaries of the main river at the installation sites of the heat exchangers 1 can exceed the surface marks of the low floodplain 13 and spread over a considerable area (Fig. 3). Due to overflow through the crests of the dams, only excess flow is discharged into the lower downstream areas, which should not exceed the total flow rate of the outflow of water to the floodplain in the main river channel from the temporary reservoirs located on the tributaries. In order to achieve such a correspondence, elevations of dam crests are increased by regulating the ventilation intensity of heat exchangers 1 or the number of ice dams on tributaries of the main river is increased. Ice dams are created by installing heat exchangers 1 in the upper tributaries of the main river, on which it is necessary to protect the adjacent territory from flooding during high water, and (or) create cascades of dams on one or several tributaries. In spring, at a positive air temperature, the mode of melting of the ice mounds 5 is regulated by increasing or decreasing the intensity of ventilation of the heat exchangers 1, which ensures the regulation of the height of the crests of the ice dams, the volume of temporary reservoirs and, therefore, the duration of the discharge during the flood period. The ventilation rate of the heat exchangers 1 is regulated by the position of the shutters 4 on the ventilation risers 2. With a large number of heat exchangers 1 on the tributaries of the main river, remote control of the shutters 4 is provided.

The accumulation of high-water runoff in temporary reservoirs allows to extend the period of water discharge and thereby smooth out the peak of high water and with the gradual, almost self-regulating discharge of meltwater into the main channel, flooding of the territory in the lower reaches of the river is prevented. At the same time, the ecological load on the environment is reduced, since the alienation of lands and long-term flooding of the territory allocated to reservoirs are excluded, and the violation of the hydrological regime and fish habitat occurs only for a relatively short period, and in those periods when there is no active course (migration ) fish. After the gradual melting of the ice dams, the hydrological regime of the tributaries and the main river is completely restored to that observed under natural conditions, which ensures the environmental requirements and the requirements of various water users.

Claims (1)

A method of regulating river flow to prevent flooding, which consists in the accumulation of flood water in temporary reservoirs formed by creating permeable dams in the channels, characterized in that in the transverse sections of the river tributaries at the bottom level, tubular heat exchangers are installed that are hermetically connected to uneven ventilation risers communicating with the atmosphere, which are placed on opposite shores, in the pre-underwater period provide active air ventilation, I have its temperature below 0 ° C, through the heat exchangers and by freezing Photo form artificial icing weir, in the spring at a positive air temperature is adjusted melting ice accumulation mode by increasing or decreasing the intensity of the ventilation heat exchangers.

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